Solar flare hard X-ray spikes observed by RHESSI: a case study
Solar flare hard X-ray spikes observed by RHESSI: a case study
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RHESSI 观测到的太阳耀斑硬 X 射线尖峰：案例研究
DOI：
10.1051/0004-6361/201118609
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发表时间：
2012-10
期刊：
影响因子：
--
通讯作者：
H. Wang
中科院分区：
文献类型：
--
作者：
J. Qiu;J. X. Cheng;G. J. Hurford;Y. Xu;H. Wang
上下文在70年代和80年代，空间望远镜发现了亚秒级时间尺度的快速变化的硬X射线尖峰，并且也被Ramaty高能太阳光谱成像仪（RHESSI）观测到。这些事件表明耀斑能量释放是分散的。目标。在本文中，我们分析硬X射线尖峰观测RHESSI了解他们的时间，光谱和空间特性。方法.将新近开发的解调程序应用于RHESSI观测的几个能带的硬X射线光变曲线。硬X射线尖峰是从解调的耀斑光变曲线中选择的。我们测量了这些尖峰的持续时间、能量依赖的时间延迟和计数谱指数。我们还从RHESSI映射中定位了发射这些尖峰的硬X射线源，该映射与可见光和紫外波长的成像观测相协调。结果我们确定快速变化的结构，1秒的硬X射线在五个耀斑的崛起。这些硬X射线尖峰可以在超过100 keV的光子能量下观察到。它们表现出急剧的上升和衰减，持续时间（FWHM）小于1 s。能量依赖的时间滞后存在于一些尖峰。可以看出，尖峰表现出更硬的光谱比基本组件，通常由0.5的光谱指数时，他们被拟合到幂律分布。RHESSI在25 - 100 keV下的清晰图（以尖峰峰值为中心的2 s积分）表明，硬X射线尖峰主要由极性相反的磁场中的双足点源发射。RHESSI映射分辨率为4 00，硬X射线尖峰图没有表现出可检测的空间结构的差异，从源发射的基础组件。协调的高分辨率成像紫外和红外观测证实，硬X射线尖峰产生于嵌入在底层组件相同磁性环境中的磁性结构。一个事件的协调高节奏TRACE UV观测可能揭示了在叠加在底层组件上的尖峰时间在空间尺度1 - 200上的新结构。它们可能是硬X射线尖峰的来源。
Context. Fast-varying hard X-ray spikes of subsecond time scales were discovered by space telescopes in the 70s and 80s, and are also observed by the Ramaty High Energy S olar S pectroscopic Imager(RHESSI). These events indicate that the flare energy release is fragmented. Aims. In this paper, we analyze hard X-ray spikes observed by RHESSI to understand their temporal, spectral, and spatial properties. Methods. A recently developed demodulation code was applied to hard X-ray light curves in several energy bands observed by RHESSI. Hard X-ray spikes were selected from the demodulated flare light curves. We measured the spike duration, the energydependent time delay, and count spectral index of these spikes. We also located the hard X-ray source emitting these spikes from RHESSI mapping that was coordinated with imaging observations in visible and UV wavelengths. Results. We identify quickly varying structures of 1 s during the rise of hard X-rays in five flares. These hard X-ray spikes can be observed at photon energies over 100 keV. They exhibit sharp rise and decay with a duration (FWHM) of less than 1 s. Energydependent time lags are present in some spikes. It is seen that the spikes exhibit harder spectra than underlying components, typically by 0.5 in the spectral index when they are fitted to power-law distributions. RHESSI clean maps at 25‐100 keV with an integration of 2 s centered on the peak of the spikes suggest that hard X-ray spikes are primarily emitted by double foot-point sources in magnetic fields of opposite polarities. With the RHESSI mapping resolution of 4 00 , the hard X-ray spike maps do not exhibit detectable di erence in the spatial structure from sources emitting underlying components. Coordinated high-resolution imaging UV and infrared observations confirm that hard X-ray spikes are produced in magnetic structures embedded in the same magnetic environment of the underlying components. The coordinated high-cadence TRACE UV observations of one event possibly reveal new structures on spatial scales 1‐2 00 at the time of the spike superposed on the underlying component. They are probably sources of hard X-ray spikes.
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DOI：
10.1086/176582
发表时间：
1995-12
期刊：
The Astrophysical Journal
影响因子：
--
作者：
M. Aschwanden;A. Benz;B. Dennis;R. Schwartz
通讯作者：
M. Aschwanden;A. Benz;B. Dennis;R. Schwartz
DOI：
10.1086/317059
发表时间：
2000-10
期刊：
The Astrophysical Journal
影响因子：
--
作者：
Haimin Wang;J. Qiu;C. Denker;T. Spirock;Hangjun Chen;P. Goode
通讯作者：
Haimin Wang;J. Qiu;C. Denker;T. Spirock;Hangjun Chen;P. Goode
DOI：
10.1086/184408
发表时间：
1984-12
期刊：
The Astrophysical Journal
影响因子：
--
作者：
A. Kiplinger;B. Dennis;K. Frost;L. Orwig
通讯作者：
A. Kiplinger;B. Dennis;K. Frost;L. Orwig
DOI：
10.1086/172442
发表时间：
1993-03
期刊：
The Astrophysical Journal
影响因子：
--
作者：
D. Neidig;A. Kiplinger;Howard S. Kohl;H. Philip;Wiborg
通讯作者：
D. Neidig;A. Kiplinger;Howard S. Kohl;H. Philip;Wiborg
影响因子：
2.8
作者：
Peter Hoyng;John C. Brown;H. F. van Beek
通讯作者：
Peter Hoyng;John C. Brown;H. F. van Beek